The Ford Barn

mlp623 · 01-03-2015, 09:23 AM

There are lots of posts about this, but I can't seem to figure out what is normal performance. I am trying to figure out how much power headlights should draw. I have adjusted the generator to put out about 8-10 V at fast idle, but when I put the lights on it jumps down to about -8 (see video). This is a 6 volt system with an original generator.The headlights are original bulb style.

This may be perfectly normal, but check out the video and let me know what you think.

https://www.youtube.com/watch?v=gYXofKG7bPc

Patrick L. · 01-03-2015, 09:41 AM

What draw do you have when just turning on the lights ? I'm wondering if you have one or more of your light connectors going to ground.
Normally setting the output at 8-10 amps at high idle should be fine when running with lights on, there may be a couple amp discharge.
For normal daylight running a setting of about 4 amps is fine and a little night running with more of a discharge is still normal.
An electronic regulator like made/sold by our very own Tom W is a good improvement.

Big hammer · 01-03-2015, 09:52 AM

Check your head light bulbs both elements maybe on 32w x2 =64 +10 tail light
74w =11amps Your 20 amp drop seams high

JOES31 · 01-03-2015, 10:04 AM

I am a little confused. Your post says you set your generator at 8 to 10 V, I assume you mean volts. Then when you turn the lights on it goes to -8 volts.

Going to -8 volts would seem impossible. Now if you're talking amps then it would make sense. I was wondering if you set it for 8-10 volts and then looked at the amp meter and are finding a -8 amp discharge.

Just wondering

mlp623 · 01-03-2015, 10:05 AM

Quote:

Originally Posted by JOES31

I am a little confused. Your post says you set your generator at 8 to 10 V, I assume you mean volts. Then when you turn the lights on it goes to -8 volts.

Going to -8 volts would seem impossible. Now if you're talking amps then it would make sense. I was wondering if you set it for 8-10 volts and then looked at the amp meter and are finding a -8 amp discharge.

Just wondering

Yes, your correct - meant amps.

Kurt in NJ · 01-03-2015, 10:39 AM

Sponsored Links (Register now to hide all advertisements)

If you read the owners instruction book you will see that a discharge with the lights on is normal, that the charge rate is to be set for the use the car gets so the battery stays charged ---a balance is acheived, charging more than is needed during daylight use to make up for the negative charge of nightime use

On my car the lights draw 14 amps, I have 35 watt halogen bulbs, for my local driving I have had a 14 amp charge rate, i do 50% driving with lights on, I never charge the battery except by driving, if I take a long daylight drive I prevent overcharging by turning on the lights, ---after 16 years of use my Optima battery died, only had a charger on it for 10 min it's whole life (was totally dead once from leaving the ignition on for 3 months--hand cranked it, generator charged it) ---it works for me, you may need a different charge rate, 14 amps is near upper limit for safe generator operation, I leave the cover band off for cooling, ---actually I never put the cover band back on after the halogen bulbs, i used to use 50 cp bulbs, to make them bright I used to kick the charge rate all the way up, about 18 amps, then back down for day driving, 18 amps is in kill generator quick range, but it survived, havn't had any need to touch it in 40+ years of use---although I guess it is due for a going through, after all how good could a 16 year old have done on the first generator rebuild

Tom Wesenberg · 01-03-2015, 10:42 AM

What bulbs are you using?
They are either high wattage, or you have a short.
I'm stock headlamps and single taillight, and it draws about 8 amps with the engine off and lights on.

mlp623 · 01-03-2015, 01:39 PM

The bulbs are 50/32 but I get -20 on either high or low, which points to short, right. There isn't a ground wire installed (yet). I see the procedure in les Andrews. Are there any other ways to ensure a good ground or troubleshoot?

Tom Wesenberg · 01-03-2015, 03:29 PM

Seems you already have a good ground to draw that many amps.

You also might want to clip a quality ammeter in place of the fuse to get an accurate amp reading. If you don't use a fuse, then just unscrew the horn/lights terminal from the cutout and put the meter is series there.

Big hammer · 01-03-2015, 06:58 PM

Like Tom said you have a really good ground :-) Two elements on at same time in a bulb would draw to many amps. It's easy to check, lift head light lens and have a look.

Tom Wesenberg · 01-03-2015, 07:21 PM

Quote:

Originally Posted by Big hammer

Like Tom said you have a really good ground :-) Two elements on at same time in a bulb would draw to many amps. It's easy to check, lift head light lens and have a look.

Good point about both filaments lit at the same time, because many repro contacts are too large a diameter and can touch each other. I've seen it happen at the connection to the light bucket. A welding helmet is a good way to view them.

mlp623 · 01-03-2015, 08:32 PM

OK, I have to admit. I am a little confused

So I have a good ground - sounds more like a short. I wouldn't be surprised if both filaments were on - I don't notice much difference from low and high beam. When I look at the assembly, it looks different that the parts available for repair. I also see there is a lot of chatter about the sockets. Good news is I am all for Bratton's quality parts. Bad news is I can't figure out what I have to start with. I am open to re-building correctly if that is the best option.

Tom Wesenberg · 01-03-2015, 09:08 PM

Make sure the filaments are top and bottom when installed, and not side by side as some repro parts were. We ran into that at our club's spring tune up clinic.

Bright and dim is more about the reflector aiming the beam down more for DIM, than making the light output dimmer.

Mike V. Florida · 01-04-2015, 12:13 AM

Do you have a welding helmet? look at the bulbs when on. I too believe that you have a short and both filaments are on at the same time.

JOES31 · 01-04-2015, 12:06 PM

If you had a direct shot it would peg the ammeter all the way negative and you would see some smoke and could start a fire so from what you have said I would say there is something else drawing the power other than a short. The suggestions of both filaments lighting on both bulbs sounds like it could be the problem however, I would disconnect or remove the bulbs on everything except the headlamps. This should let you isolate if the headlights are the problem. If the draw goes away then it is in the taillights or cowl lights if you have them.

One more thing. The ammeters are really lousy. It could be the meter is not reading correctly and I defy anyone to find a new quality repo ammeter. I had to go through 3 to get one good one. As someone previously suggested you need to put a good test meter to check the accuracy of the meter you have in the car.

mlp623 · 01-06-2015, 03:14 PM

Thanks. I did verify that the filaments are top and bottom. I don't have a welding mask but can probably get access to one soon. At my Model A Club meeting last night it was suggested that I put a test light on the contacts - only 1 should be hot for either low or high. I'll keep you posted.

01-03-2015, 09:23 AM	#1
mlp623 Senior Member Join Date: Nov 2014 Location: Chatham, NJ Posts: 136	Generator Adjustment There are lots of posts about this, but I can't seem to figure out what is normal performance. I am trying to figure out how much power headlights should draw. I have adjusted the generator to put out about 8-10 V at fast idle, but when I put the lights on it jumps down to about -8 (see video). This is a 6 volt system with an original generator.The headlights are original bulb style. This may be perfectly normal, but check out the video and let me know what you think. https://www.youtube.com/watch?v=gYXofKG7bPc

01-03-2015, 09:41 AM	#2
Patrick L. Senior Member Join Date: May 2010 Location: Largo Florida Posts: 7,225	Re: Generator Adjustment What draw do you have when just turning on the lights ? I'm wondering if you have one or more of your light connectors going to ground. Normally setting the output at 8-10 amps at high idle should be fine when running with lights on, there may be a couple amp discharge. For normal daylight running a setting of about 4 amps is fine and a little night running with more of a discharge is still normal. An electronic regulator like made/sold by our very own Tom W is a good improvement.

01-03-2015, 09:52 AM	#3
Big hammer Senior Member Join Date: Jun 2014 Location: Land of Lincoln Posts: 3,127	Re: Generator Adjustment Check your head light bulbs both elements maybe on 32w x2 =64 +10 tail light 74w =11amps Your 20 amp drop seams high

01-03-2015, 10:04 AM	#4
JOES31 Senior Member Join Date: Apr 2014 Location: La Verne California Posts: 272	Re: Generator Adjustment I am a little confused. Your post says you set your generator at 8 to 10 V, I assume you mean volts. Then when you turn the lights on it goes to -8 volts. Going to -8 volts would seem impossible. Now if you're talking amps then it would make sense. I was wondering if you set it for 8-10 volts and then looked at the amp meter and are finding a -8 amp discharge. Just wondering

01-03-2015, 10:39 AM	#6
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,156	Re: Generator Adjustment Sponsored Links (Register now to hide all advertisements) If you read the owners instruction book you will see that a discharge with the lights on is normal, that the charge rate is to be set for the use the car gets so the battery stays charged ---a balance is acheived, charging more than is needed during daylight use to make up for the negative charge of nightime use On my car the lights draw 14 amps, I have 35 watt halogen bulbs, for my local driving I have had a 14 amp charge rate, i do 50% driving with lights on, I never charge the battery except by driving, if I take a long daylight drive I prevent overcharging by turning on the lights, ---after 16 years of use my Optima battery died, only had a charger on it for 10 min it's whole life (was totally dead once from leaving the ignition on for 3 months--hand cranked it, generator charged it) ---it works for me, you may need a different charge rate, 14 amps is near upper limit for safe generator operation, I leave the cover band off for cooling, ---actually I never put the cover band back on after the halogen bulbs, i used to use 50 cp bulbs, to make them bright I used to kick the charge rate all the way up, about 18 amps, then back down for day driving, 18 amps is in kill generator quick range, but it survived, havn't had any need to touch it in 40+ years of use---although I guess it is due for a going through, after all how good could a 16 year old have done on the first generator rebuild

01-03-2015, 10:42 AM	#7
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Generator Adjustment What bulbs are you using? They are either high wattage, or you have a short. I'm stock headlamps and single taillight, and it draws about 8 amps with the engine off and lights on.

01-03-2015, 01:39 PM	#8
mlp623 Senior Member Join Date: Nov 2014 Location: Chatham, NJ Posts: 136	Re: Generator Adjustment The bulbs are 50/32 but I get -20 on either high or low, which points to short, right. There isn't a ground wire installed (yet). I see the procedure in les Andrews. Are there any other ways to ensure a good ground or troubleshoot?

01-03-2015, 03:29 PM	#9
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Generator Adjustment Seems you already have a good ground to draw that many amps. You also might want to clip a quality ammeter in place of the fuse to get an accurate amp reading. If you don't use a fuse, then just unscrew the horn/lights terminal from the cutout and put the meter is series there.

01-03-2015, 06:58 PM	#10
Big hammer Senior Member Join Date: Jun 2014 Location: Land of Lincoln Posts: 3,127	Re: Generator Adjustment Like Tom said you have a really good ground :-) Two elements on at same time in a bulb would draw to many amps. It's easy to check, lift head light lens and have a look.

01-03-2015, 09:08 PM	#13
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Generator Adjustment Make sure the filaments are top and bottom when installed, and not side by side as some repro parts were. We ran into that at our club's spring tune up clinic. Bright and dim is more about the reflector aiming the beam down more for DIM, than making the light output dimmer.

01-04-2015, 12:13 AM	#14
Mike V. Florida Senior Member Join Date: May 2010 Location: South Florida Posts: 14,054	Re: Generator Adjustment Do you have a welding helmet? look at the bulbs when on. I too believe that you have a short and both filaments are on at the same time. __________________ What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

01-04-2015, 12:06 PM	#15
JOES31 Senior Member Join Date: Apr 2014 Location: La Verne California Posts: 272	Re: Generator Adjustment If you had a direct shot it would peg the ammeter all the way negative and you would see some smoke and could start a fire so from what you have said I would say there is something else drawing the power other than a short. The suggestions of both filaments lighting on both bulbs sounds like it could be the problem however, I would disconnect or remove the bulbs on everything except the headlamps. This should let you isolate if the headlights are the problem. If the draw goes away then it is in the taillights or cowl lights if you have them. One more thing. The ammeters are really lousy. It could be the meter is not reading correctly and I defy anyone to find a new quality repo ammeter. I had to go through 3 to get one good one. As someone previously suggested you need to put a good test meter to check the accuracy of the meter you have in the car.

01-06-2015, 03:14 PM	#16
mlp623 Senior Member Join Date: Nov 2014 Location: Chatham, NJ Posts: 136	Re: Generator Adjustment Thanks. I did verify that the filaments are top and bottom. I don't have a welding mask but can probably get access to one soon. At my Model A Club meeting last night it was suggested that I put a test light on the contacts - only 1 should be hot for either low or high. I'll keep you posted.